The United Nations World Health Organization (WHO) today welcomed news that a potential malaria vaccine could protect toddlers in Africa, and stressed the vital role of the continent's institutions in developing tools to fight a major killer of children.
Dr. Marie-Paule Kieny, Director of WHO's Initiative for Vaccine Research (IVR), described the clinical results of the RTS,S/AS02A vaccine as a "breakthrough" that proved the possibility of an effective malaria vaccine, but added that much more work on it was needed.
"This step forward also highlights the crucial role that African governments, research institutions and scientists in the malaria-endemic areas of Africa play in developing tools and strategies against this major killer of children," Dr. Kieny said.
The RTS,S/AS02A vaccine is the first in 25 years to demonstrate a significant capability to protect human adult volunteers against an experimental infection with the malaria parasite. The results also show that the vaccine induces protection against malaria in children between one and four years old in Africa.
From April 2003 to May 2004, three doses of RTS, S/AS02A were given to 2,022 one- to four-year-olds in Maputo Province, Mozambique, which has perennial malaria transmission mostly due to Plasmodium falciparum, one of the most common and the most deadly type of malaria parasites.
The candidate vaccine delayed the time to new infections with the malaria parasite by 45 per cent, cut by nearly a third the risk of a clinical episode of malaria and reduced by 57.7 per cent new episodes of severe malaria - which may lead child survivors to suffer from learning impairments or brain damage.
Dr. Kieny said that although that last figure was less than that of classical childhood vaccines, which often record rates greater than 80 per cent, "the outcome of the trial is very encouraging for the future of malaria vaccines because it is the first demonstration of any efficacy against severe malaria in children."
According to WHO, more than 40 per cent of the world's children live in malaria-endemic countries, where there are 300 million to 500 million infections each year. Around 90 per cent of the 1 million deaths each year due to malaria occur in Africa, mostly in children, and the illness is the leading cause of under-five mortality on the continent.